1. Technical Field
The present invention relates to a long-wavelength optical fiber amplifier, and more particularly, to an optical fiber amplifier for amplifying a long-wavelength optical signal in the range of 1580 nanometers.
2. Related Art
In an optical transmission system, an erbium doped fiber amplifier (EDFA) can be used to directly amplify optical signals which become weak during transmission. This amplification of the optical signals can be performed without converting the optical signals into electrical signals. Thus, the transmission distance can be markedly increased.
I have found that a large amount of power can be required when amplifying a long-wavelength optical signal in the wavelength range of 1580 nanometers (nm). Unfortunately, there is not currently available an adequate method for efficiently and conveniently amplifying a long-wavelength optical signal.